Diagram of the Solstices and Equinoxes

This diagram shows the positions of the Sun on the days of the solstices and equinoxes. The center constitutes the observer's position, facing south (the diagram's top). The thin yellow band framing the diagram is the horizon. Six yellow circles connected by three red arcs of decreasing size indicate sunrise (left) and sunset (right) at the summer solstice, the spring and autumn equinoxes, and the winter solstice respectively, while the arcs themselves show the Sun's path above the horizon on these days. At the arcs' midpoints are the midday Suns of the solstices and equinoxes. Six straight red lines on either side of the midday Suns indicate the Sun's positions at the third and ninth hours on these days.

Provenance

Provenance (from the French provenir, 'to come from/forth') is the chronology of the ownership, custody, or location of a historical object.

Gruel and Englemann Collection, Paris [1]; acquired by Henry Walters, Baltimore, 1903; by bequest to Walters Art Museum, 1931.

[1] no. 131, bookplate on inside upper board